Removal of ambient noise from video recordings is an area in which many different approaches exist. A common theme, though, is that all such approaches seek to be the most effective without harming the integrity of the input signal.
Many current methods of attenuating or removing ambient noise in video recordings at utilize the principle of “spectral subtraction”. In this approach the unwanted component of the signal is estimated and afterwards subtracted from the signal, with the portion of the signal that remains after subtraction presumably being the desired signal.
The undesirable component of the signal is might be either automatically determined using a targeted search in the signal for sequences that do not contain speech to use in estimating the undesirable components, or in other cases the user might have to manually select a noise sample (e.g., a section of the sample that contains only the undesirable/background component). The latter approach is the most common approach in software based solutions.
Other approaches for attenuation of ambient noise known in the art (for example “beam forming” or “active noise suppression”) require a number of simultaneously recorded input signals from differently positioned microphones.
The many different approaches are due ion part to the ultimate goal of the noise reduction effort. For example, different methods might be utilized in hearing aids, telephones and intercom systems that process band limited speech signals. For these sorts of devices, a central goal might be to increase the understandability audibility of speech in general.
Background noise that is too loud is a common side effect when utilizing semi-professional equipment for video recording. One reason for this is because of the microphones that are integrated into the recording video cameras that are typically used. In the professional sector however external microphones are utilized which are normally located near or around the current speaker. That significantly minimizes the chances that there will be a problem with the volume of the ambient noise compared to the volume of the speech.
Known methods to reduce ambient noise in hearing aids, intercoms and telephones also usually have to deal with the limitations regarding computing capacity, real-time capacity (low latency) and memory requirements.
The methods which are already state of the art usually work exclusively in the frequency domain or the time domain. The instant invention utilizes a mixed approach, wherein the digital signal is separated into single spectral components. These frequency components are than transformed back into the time domain, in which the analysis takes place. The instant invention is therefore a method which operates in the frequency domain as well as in the time domain.
Thus, what is needed is a system and method for computer devices that supports a user when attenuating random ambient noise, including wind noise in video recordings with speech content, wherein the system is directly usable as a software module in video and/or audio editing software.
Heretofore, as is well known in the media editing industry, there has been a need for an invention to address and solve the above-described problems. Accordingly it should now be recognized, as was recognized by the present inventors, that there exists, and has existed for some time, a very real need for a system and method that would address and solve the above-described problems.
Before proceeding to a description of the present invention, however, it should be noted and remembered that the description of the invention which follows, together with the accompanying drawings, should not be construed as limiting the invention to the examples (or preferred embodiments) shown and described. This is so because those skilled in the art to which the invention pertains will be able to devise other forms of the invention within the ambit of the appended claims.